package com.hmdp.utils;
import cn.hutool.core.lang.UUID;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import java.util.Collections;
import java.util.concurrent.TimeUnit;

public class SimpleRedisLock implements ILock{
    private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;
    static {
        UNLOCK_SCRIPT = new DefaultRedisScript<>();
        UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));
        //直接再res去找
        UNLOCK_SCRIPT.setResultType(Long.class);
    }
    private String name;
    private StringRedisTemplate stringRedisTemplate;

    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {
        this.name = name;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    private static final String KEY_PREFIX="lock:";
    private static final String ID_PREFIX= UUID.randomUUID().toString(true)+"-";

    @Override
    public boolean tryLock(long timeoutSec) {
        // 获取线程标示
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        //long threadId = Thread.currentThread().getId();

        // 获取锁
        Boolean success = stringRedisTemplate.opsForValue()
                .setIfAbsent(KEY_PREFIX + name, threadId, timeoutSec, TimeUnit.SECONDS);
        return Boolean.TRUE.equals(success);
    }

    @Override
    public void unLock() {
        // 调用lua脚本
        stringRedisTemplate.execute(
                UNLOCK_SCRIPT,
                Collections.singletonList(KEY_PREFIX + name),
                ID_PREFIX + Thread.currentThread().getId());

    }
        /*
        String threadId = ID_PREFIX+Thread.currentThread().getId();
        String id = stringRedisTemplate.opsForValue().get(KEY_PREFIX + name);
        //这里我们需要先去redis拿到返回值才可以进行下面的判断。所以不可以用redis事物
        if(threadId.equals(id)){
            stringRedisTemplate.delete(KEY_PREFIX+name);
        }
        //通过del删除锁
        stringRedisTemplate.delete(KEY_PREFIX + name);
         */



}
